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Finding the Fourth Proportional to 420.49, 627.55 and 409.55

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Solution

The fourth proportional to 420.49, 627.55 and 409.55 is: 611.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.49 : 627.55 = 409.55 : x
  2. Step 2: Convert to fraction form
    420.49/627.55 = 409.55/x
  3. Step 3: Cross multiply
    420.49x = 627.55 × 409.55
  4. Step 4: Simplify right side
    420.49x = 257,011.05
  5. Step 5: Solve for x
    x = 257,011.05/420.49
  6. Step 6: Final answer
    x = 611.23

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.